It is the intended mechanic, it is exactly the same for Retaliation, if for ex as a Warrior you make 100ed Blade to Confusion or Retal you will kill yourself.
But for ex Warrior has reliable cleanse or invuls that you can bypass this. Revenant, specially Dragon/Shiro does not have it. So I think they should have something that will reduce the effectiveness of confusion.
The difference is that 100 blades only hits you with 1 tick of confusion on activation, and not for every hit, you still get hit with retaliation on every strike though.
That’s how it works with every multi-hit channeled skill, such as pistolwhip / blurred frenzy / 100 blades.
This is cause retaliation triggers on hit, and confusion triggers on skill use.
It even says so in the tooltip of confusion “Damage received on skill activation; stacks intensity.”.
When I’m using unrelenting assault, I activate ONE skill, yet I get hit 7 times.